1. Field of the Invention
The present invention relates to mechanical blending systems for gases or liquids, and more particularly to mechanical blending systems which blend two or more fluids proportionally throughout an operation range.
2. History of the Prior Art
There has been a continual search for a simpler means to blend fluids into desirable proportions. Some of the prior art devices include: venturi systems which move a fluid into the high velocity portion of the venturi for blending; systems which utilize a two ported rotating piston; systems using a two ported sleeve valve; systems with separate valves linked together; systems which use variable ports with metering pins; systems which utilize mechanical dampers linked together; systems which use target vanes to sense primary flow and position a piston valve; and systems which utilize electronic devices to position valve plates. However, these devices generally require a sensing and control means to assure proper performance.
It would be a distinct advantage to have a simple blending device which would be capable of delivering a blend which is proportional throughout its operational range, and a blending device which would not require complex sensing and control means. The present invention provides for a very compact and simple blending device having a single valve plate and a single valve seating plane which can contain two or more ports, and provides for a proportional blending of fluids throughout its operational range.